X-FLARE! Big sunspot AR1520 unleashed an X1.4-class solar flare on July 12th. Because the sunspot is directly facing Earth, everything about the blast was geoeffective. For one thing, it hurled a coronal mass ejection (CME) directly toward our planet. According to a forecast track prepared by analysts at the Goddard Space Weather Lab, the CME will hit Earth on July 14th around 09:17 UT (+/- 7 hours) and could spark strong geomagnetic storms.

The explosion also strobed Earth with a pulse of extreme UV radiation, shown here in a movie recorded by NASA's Solar Dynamics Observatory:

The UV pulse partially ionized Earth's upper atmosphere, disturbing the normal propagation of radio signals around the planet. Monitoring stations in Norway, Ireland and Italy recorded the sudden ionospheric disturbance.

Finally, solar protons accelerated by the blast are swarming around Earth. The radiation storm, in progress, ranks "S1" on NOAA space weather scales, which means it poses no serious threat to satellites or astronauts. This could change if the storm continues to intensify. Stay tuned.

SOUTH POLE AURORAS: In a possible preview of the light show to come, bright auroras have been dancing over Earth's south pole. Robert Schwarz took this picture on July 12th from the grounds of the Amundsen-Scott South Pole Station:

"Yesterday we had some of the best auroras I've seen," says Schwarz.

Despite its high latitude, the South Pole is not always a good place to see the lights because it is often located in the "doughnut hole" of the aurora oval. July 12th was an exception: "Look carefully at the picture and you can see the actual Pole in the foreground" Schwarz points out.

NOAA forecasters estimate a 55% chance of strong polar geeomagnetic storms on July 14th when a CME is expected to crash into Earth's magnetic field. More South Pole auroras could be in the offing.

Potentially Hazardous Asteroids (PHAs) are space rocks larger than approximately 100m that can come closer to Earth than 0.05 AU. None of the known PHAs is on a collision course with our planet, although astronomers are finding new ones all the time.